When I get in my truck and turn the key to the ON position (engine is not running) my oil pressure gauge goes to the top of the operation range and stays there. Once I start the truck it doesnt budge it just stays put until I turn the truck off. I know there are a lot of sending unit issues but from what I understand of the sending unit is bad the gauge would read zero all the time. Any ideas?

 

Just and FYI for everyone, I talked to my local Cummins shop this morning they they said my problem is most likely the sending unit. They said unlike most sending units the one used on the 24 valve engines can act erratic and swing from 0 to the top of the scale and everywhere in between when they go bad. The ones they are selling are supposed to be a much better unit the only bummer is the plug is different so you have to buy a pigtail and replace the factory plug on the truck. New sending unit $79, pigtail $11.

 

How many wires in the new pigtail? Still 3?

 

I know the 12 valve unit is different, but have you checked with Car Quest?

 

I have had my sending unit replaced twice in 88000 miles, they don't seem to last too long. Guage very erratic with a bad sender.

 

Replaced mine at 140K miles. It had the same symptoms. It would always indicate the same pressure, even with KOnEOff.
The replacement was a like-for like fit - no adapter. When I get off othe road I can look up the part number for you. In 2001-1/2 they went to a different sending unit which was essentially just a make-or-break style (idiot light) and the computer used an algorythm to generate a pressure signal that would appear correct based on engine speed and temperature. Make sure that is NOT the sending unit the parts guy is trying to sell you!

Dry Creek

 

my oil pressure guage is also staying at top of operating range while the key is on, running or not. checked price at napa and they said they could order one for like $190. hope they are cheaper than that from the dealer